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Background: Osteosarcoma (OS) is a common disease in the world, and its pathogenesis is still unclear. This study aims to identify the key genes that promote the proliferation, invasion, and metastasis of osteosarcoma cells. Method: GSE124768 and GSE126209 were downloaded from the Gene Expression Omnibus (GEO) database. The gene ontology and enrichment pathway were analyzed by FunRich software. qPCR and Western blot were used to detect the gene expression. After gene knockdown, Transwell and wound healing assays were conducted on osteosarcoma cells to detect whether the genes were defined before enhancing the invasion of osteosarcoma. Results: Totally, 341 mRNAs were found to be regulated differentially in osteosarcoma cells compared to osteoblasts. In addition, the expression level of Serglycin (SRGN) in osteosarcoma cells was higher than that in human osteoblasts. The invasion and proliferation ability of osteosarcoma cells with upregulated Serglycin was significantly increased, and on the contrary, decreased after Serglycin knockdown. Moreover, we preliminarily found that Serglycin may associate with the JAK/STAT signaling pathway. Conclusions: By using microarray and bioinformatics analyses, differently expressed mRNAs were identified and a complete gene network was constructed. To our knowledge, we describe for the first time Serglycin as a potential biomarker.

The metabolic change of tumor cells is an extremely complicated process that involves the intersection and integration of various signal pathways. Compared with normal tissues, cancer cells show distinguished metabolic characteristics called metabolic reprogramming, which has been considered as a sign of cancer occurrence. With the deepening of tumor research in recent years, people gradually found that amino acid metabolism played crucial roles in cancer progression. Long non-coding RNAs (lncRNAs), which are implicated in many important biological processes, were firstly discovered dysregulating in cancer tissues and participating in extensive regulation of tumorigenesis. This review focuses on the reprogramming of amino acid metabolism in cancers and how lncRNAs participate in the regulatory network by interacting with other macromolecular substances. Understanding the functions of lncRNA in amino acid reprogramming in tumors might provide a new vision on the mechanisms of tumorigenesis and the development of new approaches for cancer therapy.

Introduction Breast cancer metastasis suppressor 1 like (BRMS1-like)was first reported to be a component of the Sin3-HDAC complex, but the role in the progression of cancers was largely unknown. Our previous study reported that BRMS1L promoted the metastasis of breast cancer through facilitating the recruitment of HDAC complex to the promoter FZD10, and hence suppressing the transcription of FZD10. Methods In this study, we detected the expression level of BRMS1L in esophageal squamous cell carcinoma (ESCC). The effect of BRMS1L in TE-1D (knockdown) and ECA-109 (overexpression) cell lines was explored by transwell assays, wound healing assays, and cell adhesion assays. Quantitative real‑time PCR, Western blot analysis, and luciferase assays were used to detect the interaction of the CBP/P300-BRMS1L-ITGA7 axis. Results In the present study, we found that knockdown of BRMS1L promoted the migration, invasion, and epithelial-mesenchymal transition (EMT). Conversely, overexpression of BRMS1L inhibited the migration and invasion of ESCC. Mechanistically, BRMS1L exerted their metastasis-suppressing role via transcriptionally repress ITGA7 expression. Moreover, we revealed that CBP/p 300 regulated the expression of BRMS1L and might be responsible for the down-regulation of BRMS1L in ESCC. Conclusion Collectively, we identified the role of CBP/p300-BRMS1L-ITGA7 axis in the metastasis of ESCC.

Background: WT161 is a recently discovered histone deacetylase 6 (HDAC6) inhibitor which shows anti-tumor effects on multiple myelomas and breast cancer. However, the role of WT161 in retinoblastoma remains unclear. The aim of this study is to explore the role of WT161 in retinoblastoma and its underlying mechanisms. Methods: The anti-proliferation of WT161 on retinoblastoma cells was examined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and soft agar colony formation assay. Cell apoptosis was analyzed using flow cytometer. WT161 and DDP synergistic effect was evaluated by isobologram analysis using CompuSyn software. Results: WT161 suppressed the cell growth and induced apoptosis of retinoblastoma cells in a dose- and time-dependent manner. Mechanistically, WT161 increases the transcription of Bad through activating Bad promoter. Chromatin immunoprecipitation (ChIP) assay showed WT161 treatment increased acetylated histone H3 (AcH3) and acetylated histone H4 (AcH4) on the Bad promoter in retinoblastoma cells. In addition, WT161 shows synergistically inhibitory effects on retinoblastoma cell combined with cisplatin. Conclusions: These results indicate that WT161, as a selective HDAC6 inhibitor, is a promising agent against retinoblastoma.

Osteoarthritis (OA) is a joint degenerative disease, which is prominent in the middle-aged and elderly population, often leading to repeated pain in the joints of patients and seriously affecting the life quality of patients. At present, the treatment of OA mainly depends on the surgery and drug treatment. Nevertheless, these treatments still face many problems, such as surgical safety, complications, and drug side effects. Exosomes can be secreted and released by multiple cell types and have lipid bilayer membranes and contain abundant biological molecules, including proteins, lipids, and nucleic acids. Moreover, exosomes play a critical role in local and distal intercellular and intracellular communication. In recent years, several studies have found that exosomes can regulate the progression of OA and have a potential efficacy for OA treatment. Thus, in this article, we summarize and review the relevant research of exosomes in OA and emphasize the importance of exosomes in the development of OA.

Background: Osteosarcoma (OS) is a tumor with a high malignancy level and a poor prognosis. First-line chemotherapy for OS has not been improved for many decades. Bromodomain and extra terminal domain (BET) and histone deacetylase (HDACs) regulate histone acetylation in tandem, and BET and HDACs have emerged as potential cancer therapeutic targets. Methods: Cell proliferation, migration, invasion, colony formation, and sphere-forming assay were performed with the two inhibitors alone or in combination to evaluate their suppressing effect on malignant properties of OS cells. The apoptosis and cells-cycle profile were measured by flow cytometry. The synergistic inhibitory effect of OTX015/WT-161 on tumor was also examined in a nude mouse xenograft model. Results: The combined therapy of OTX015/WT-161 synergistically inhibited the growth, migration, and invasion and induced apoptosis, resulted in the G1/S arrest of OS cells. Additionally, OTX015/WT-161 inhibits the self-renewal ability of OS stem cells (OSCs) in a synergistic manner. Further mechanistic exploration uncovered that the synergistic downregulation of β-catenin by OTX015-mediated suppression of FZD2 and WT-161-mediated upregulation of PTEN may be responsible for the synergistic effect. Finally, the result of an in vivo assay showed that tumor xenografts were significantly decreased after treatment with OTX015/WT-161 combination compared with OTX015 or WT-161 alone. Conclusion: Our findings in this study demonstrated that OTX015 and WT-161 had a synergistic anti-cancer efficacy against OS, and their combination might be a promising therapeutic strategy for OS.

Background: WT161, as a selective HDAC6 inhibitor, has been shown to play anti-tumor effects on several kinds of cancers. The aim of the present study is to explore the roles of WT161 in osteosarcoma and its underlying mechanisms. Methods: The anti-proliferative effect of WT161 on osteosarcoma cells was examined using MTT assay and colony formation assay. Cell apoptosis was analyzed using flow cytometer. The synergistic effect was evaluated by isobologram analysis using CompuSyn software. The osteosarcoma xenograft models were established to evaluate the anti-proliferative effect of WT161 in vivo. Results: WT161 suppressed the cell growth and induced apoptosis of osteosarcoma cells in a dose- and time-dependent manner. Mechanistically, we found that WT161 treatment obviously increased the protein level of PTEN and decreased the phosphorylation level of protein kinase-B (AKT). More importantly, WT161 showed synergistic inhibition with 5-FU on osteosarcoma cells in vitro and in vivo. Conclusions: These results indicate that WT161 inhibits the growth of osteosarcoma through PTEN and has a synergistic efficiency with 5-FU.

Long non-coding (lnc)RNA MIR17HG has been identified as a oncogene whose roles in acute myeloid leukemia (AML) remain unclear. The present study aimed to investigate the role of lncRNA MIR17HG in AML. Differential expression of MIR17HG in AML was determined by reverse transcription-quantitative PCR. Overexpression assays and dual luciferase reporter assays were performed to determine the relationship between MIR17HG and microRNA (miR)-21, and apoptosis was analyzed by using an apoptosis assay. The results showed that the expression of MIR17HG was decreased in AML, which was further decreased following homoharringtonine (HHT)-based chemotherapy. Bioinformatics analysis predicted that miR-21 could bind with MIR17HG. However, miR-21 overexpression had no effect on the expression level of MIR17HG. Dual luciferase reporter assays were performed to verify the direct interaction between miR-21 and MIR17HG. In addition, overexpression of MIR17HG and miR-21 in AML cell lines up- and downregulated the expression level of PTEN, respectively. Furthermore, cell apoptosis showed that MIR17HG and PTEN overexpression enhanced cell apoptosis following cell treatment with HTT. However, miR-21 overexpression exerted the opposite effect, since it reversed the effects of MIR17HG and PTEN overexpression in AML cell apoptosis. In conclusion, the current study suggested that MIR17HG could regulate the miR-21/PTEN axis to modulate the chemoresistance of AML cells.

Osteosarcoma is the most frequent primary bone tumor with poor prognosis. Through RNA-sequencing of 100,987 individual cells from 7 primary, 2 recurrent, and 2 lung metastatic osteosarcoma lesions, 11 major cell clusters are identified based on unbiased clustering of gene expression profiles and canonical markers. The transcriptomic properties, regulators and dynamics of osteosarcoma malignant cells together with their tumor microenvironment particularly stromal and immune cells are characterized. The transdifferentiation of malignant osteoblastic cells from malignant chondroblastic cells is revealed by analyses of inferred copy-number variation and trajectory. A proinflammatory FABP4+ macrophages infiltration is noticed in lung metastatic osteosarcoma lesions. Lower osteoclasts infiltration is observed in chondroblastic, recurrent and lung metastatic osteosarcoma lesions compared to primary osteoblastic osteosarcoma lesions. Importantly, TIGIT blockade enhances the cytotoxicity effects of the primary CD3+ T cells with high proportion of TIGIT+ cells against osteosarcoma. These results present a single-cell atlas, explore intratumor heterogeneity, and provide potential therapeutic targets for osteosarcoma., Osteosarcomas are difficult to treat and have a limited response to immunotherapy. Here, the authors analyse osteosarcomas at the single-cell level, and identify both the transdifferentiation of malignant cells and an array of immune cells that could have implications for metastasis and immunotherapy.

Hypoexpression of human major histocompatibility complex (MHC) class I is widely known to be an important strategy of immune evasion in most cases of malignancies that lead to poor prognosis. We demonstrated that mitochondrial dynamics can be exploited as an efficient target in regulating MHC-I expression and cancer immunogenicity. Clinically, MHC-I expression and fragmentation of mitochondria are both closely associated to patient survival but are negatively correlated to one another. Mechanistically, it was observed that endoplasmic reticulum (ER) stress, an integrated signal transduction pathway activated in most rapidly proliferating tumor cells, played a crucial role in connecting mitochondrial fragmentation and cancer cell immunogenicity particularly via the IRE1α-XBP-1 s axis. XBP-1 s, which is activated by imbalanced mitochondrial fission and prolonged oxidative stress, served as a potent transcription factor, promoted the expression of aminopeptidase TPP2 and destructed the applicable antigenic peptide to impede MHC-I complex maturation and the activation of adaptive immune system upon cancer antigen. Our findings highlight the importance of mitochondrial dynamics in determining solid tumor immunogenicity and suggest that mediating mitochondrial fragmentation might provide a novel approach in anti-tumor immunotherapy.

Background: WT161 as a new selective HDAC6 inhibitor has been shown to play anti-tumor effects on multiple myeloma and breast cancer. However, the role of WT161 in osteosarcoma remains unclear. The aim of this study is to explore the role of WT161 in osteosarcoma and its underlying mechanisms.Methods: The anti-proliferative effect of WT161 on osteosarcoma cells was examined using MTT assay and colony formation assay. Cell apoptosis was analyzed using flow cytometer. The synergistic effect was evaluated by isobologram analysis using CompuSyn software. The osteosarcoma xenograft models were esatablished to evaluate the anti-proliferative effect of WT161 in vivo.Results: WT161 suppressed the cell growth and induced apoptosis of osteosarcoma cells in a dose- and time-dependent manner. Mechanistically, we found that WT161 treatment obviously increased the protein expression level of PTEN and decreased the phosphorylation level of AKT. Notably, WT161 shows synergistically inhibitory effects on osteosarcoma cell combined with 5-FU. Animal experiment results show WT161 inhibits the growth of osteosarcoma tumor and further illustrates that WT161 and 5-FU have a synergistic efficiency in osteosarcoma.Conclusions: These results indicate that WT161 inhibiting the growth of osteosarcoma through PTEN and has a synergistic efficiency with 5-FU.

Purpose: The limited efficacy of chimeric antigen receptor (CAR) T-cell therapies with solid malignancies prompted us to test whether epigenetic therapy could enhance the antitumor activity of B7-H3.CAR T cells with several solid cancer types. Experimental Design: We evaluated B7-H3 expression in many human solid cancer and normal tissue samples. The efficacy of the combinatorial therapy with B7-H3.CAR T cells and the deacetylase inhibitor SAHA with several solid cancer types and the potential underlying mechanisms were characterized with in vitro and ex vivo experiments. Results: B7-H3 is expressed in most of the human solid tumor samples tested, but exhibits a restricted expression in normal tissues. B7-H3.CAR T cells selectively killed B7-H3 expressing human cancer cell lines in vitro. A low dose of SAHA upregulated B7-H3 expression in several types of solid cancer cells at the transcriptional level and B7-H3.CAR expression on human transgenic T-cell membrane. In contrast, the expression of immunosuppressive molecules, such as CTLA-4 and TET2, by T cells was downregulated upon SAHA treatment. A low dose of SAHA significantly enhanced the antitumor activity of B7-H3.CAR T cells with solid cancers in vitro and ex vivo, including orthotopic patient-derived xenograft and metastatic models treated with autologous CAR T-cell infusions. Conclusions: Our results show that our novel strategy which combines SAHA and B7-H3.CAR T cells enhances their therapeutic efficacy with solid cancers and justify its translation to a clinical setting.

Aim: This study aimed to explore the genetic and epigenetic similarities between chronic obstructive pulmonary disease (COPD) and lung adenocarcinoma (LUAD). Materials & methods: We mainly used Weighted correlation network analysis, protein–protein interaction network and pivot analysis to identify hub modules, bridge regulators, bridge genes and hub-driving genes in both diseases and carried out verifying using external datasets. Results: We identified eight bridge regulators, 19 key molecules in the COPD model and ten key molecules in the LUAD model. Moreover, we validated that CDC5L could be a reliable biomarker in COPD and may regulate cell proliferation and metastasis in LUAD via promoter methylation. Conclusion: Our results might form a theoretical foundation for future study at an epigenetic level.

MicroRNAs (miRNAs) have been recently found in the mitochondria, and were named “mitomiRs”, but their function has remained elusive. Here, we aimed to assess the presence and function(s) of mitomiRs in tongue squamous cell carcinoma (TSCC). Methods: miRNA microarray was performed in paired TSCC cell lines, Cal27 and its chemoresistant counterpart, Cal27-re. Decreased expression of mitomiRs in chemoresistant cells was characterized. The functions of mitomiRs were investigated by a series of in vitro and in vivo experiments. Results: Differential microarray analysis identified downregulation of mitomiR-5787 in Cal27-re cells. We knocked down mitomiR-5787 in parental cells and upregulated its expression in cisplatin-resistant cells. The sensitivity of TSCC cells to cisplatin was regulated by miR-5787. The glucose metabolism assay suggested that reduced expression of miR-5787 changed the balance of glucose metabolism by shifting it from oxidative phosphorylation to aerobic glycolysis. Xenograft experiments in BALB/c-nu mice further verified the in vitro results. Reduced expression of miR-5787 contributes to chemoresistance in TSCC cells by inhibiting the translation of mitochondrial cytochrome c oxidase subunit 3 (MT-CO3). The prognostic analysis of 126 TSCC patients showed that the patients with low expression of miR-5787 and/or MT-CO3 had poor cisplatin sensitivity and prognosis. Conclusions: Mitochondrial miR-5787 could regulate cisplatin resistance of TSCC cells and affect oxidative phosphorylation and aerobic glycolysis. Downregulation of miR-5787 inhibited the translation of MT-CO3 to regulate cisplatin resistance of TSCC. Mitochondrial miR-5787 and MT-CO3 can be used as predictive biomarkers or therapeutic targets for cisplatin chemotherapy resistance.

Osteosarcoma (OS) has high heterogeneity and poor prognosis. In order to explore the molecular mechanism of OS and the tumor micro-environment (TME) on OS, we employed single-cell RNA-sequencing (scRNA-seq) on 110,745 individual cells from OS primary lesion, recurrent focal and metastatic tissues. We identified 5 main malignant subpopulations of OS cells, 3 clusters of osteoclast(OC) and 2 types of cancer-associated fibroblasts (CAFs). Further we found that the progenitor OC and, antigen presenting CAF (apCAF) were lower in lung metastatic and recurrent tumor tissues than in primary tumor tissue. M2-like macrophages were predominant in the TME myeloid cells. Inactivation state of tumor-infiltrating T cells, mainly the CD4-/CD8-T and Treg cells, existed in lung metastatic tissues. T-cell immunoreceptor with Ig and ITIM domains (TIGIT) expressed in 11 samples. We then blocked TIGIT which significantly enhancd the cytotoxic effects of primary T cells on OS cell lines. Our report represents the first use of scRNA-seq for the transcriptomic profiling of OS cells. Thus, the findings in this study will serve as a valuable resource for deciphering the intra-tumoral heterogeneity in OS and provide potential therapeutic strategies for OS in clinic.

In the original version of [this article][1] ([1][2]), there were three errors in Fig. 6: in Fig. 6A, the GADPH blots were inadvertently duplicated from Fig. 5D; in Fig. 6B, the image for Aspirin/NC was a duplicate of DMSO/sh#2; and in Fig. 6B, the Aspirin/vector image was a duplicate of Aspirin/sh#

Introduction Breast cancer metastasis suppressor 1 like (BRMS1-like)was first reported to be a component of the Sin3-HDAC complex, but the role in the progression of cancers was largely unknown. Our previous study reported that BRMS1L promoted the metastasis of breast cancer through facilitating the recruitment of HDAC complex to the promoter FZD10, and hence suppressing the transcription of FZD10. Methods In this study, we detected the expression level of BRMS1L in esophageal squamous cell carcinoma (ESCC). The effect of BRMS1L in TE-1D (knockdown) and ECA-109 (overexpression) cell lines was explored by transwell assays, wound healing assays, and cell adhesion assays. Quantitative real‑time PCR, Western blot analysis, and luciferase assays were used to detect the interaction of the CBP/P300-BRMS1L-ITGA7 axis. Results In the present study, we found that knockdown of BRMS1L promoted the migration, invasion, and epithelial–mesenchymal transition (EMT). Conversely, overexpression of BRMS1L inhibited the migration and invasion of ESCC. Mechanistically, BRMS1L exerted their metastasis-suppressing role via transcriptionally repress ITGA7 expression. Moreover, we revealed that CBP/p 300 regulated the expression of BRMS1L and might be responsible for the down-regulation of BRMS1L in ESCC. Conclusion Collectively, we identified the role of CBP/p300-BRMS1L-ITGA7 axis in the metastasis of ESCC.

Summary Cisplatin-based neoadjuvant chemotherapy has been shown to improve survival in patients with squamous cell carcinoma (SCC), but clinical biomarkers to predict chemosensitivity remain elusive. Here, we show the long noncoding RNA (lncRNA) LINC01011, which we termed cisplatin-sensitivity-associated lncRNA (CISAL), controls mitochondrial fission and cisplatin sensitivity by inhibiting BRCA1 transcription in tongue SCC (TSCC) models. Mechanistically, we found CISAL directly binds the BRCA1 promoter and forms an RNA-DNA triplex structure, sequestering BRCA1 transcription factor-GABPA away from the downstream regulatory binding region. Importantly, the clinical relevance of these findings is suggested by the significant association of CISAL and BRCA1 expression levels in TSCC tumors with neoadjuvant chemosensitivity and overall survival. We propose a new model where lncRNAs are tethered at gene promoter by RNA-DNA triplex formation, spatially sequestering transcription factors away from DNA-binding sites. Our study uncovers the potential of CISAL-BRCA1 signaling as a potential target to predict or improve chemosensitivity., Graphical Abstract, Highlights • CISAL enhances mitochondrial fission and cisplatin sensitivity in TSCC cells through BRCA1 • CISAL directly binds the BRCA1 promoter and forms an RNA-DNA triplex structure • CISAL sequesters GABPA away from regulatory binding at BRCA1 promoter • High CISAL predicts favorable neoadjuvant chemosensitivity and prognosis of TSCC patients, Biological Sciences; Molecular Biology; Cell Biology; Cancer

Purpose: The overall biological roles and clinical significance of most long noncoding RNAs (lncRNA) in chemosensitivity are not fully understood. We investigated the biological function, mechanism, and clinical significance of lncRNA NR_034085, which we termed miRNA processing–related lncRNA (MPRL), in tongue squamous cell carcinoma (TSCC). Experimental Design: LncRNA expression in TSCC cell lines with cisplatin treatment was measured by lncRNA microarray and confirmed in TSCC tissues. The functional roles of MPRL were demonstrated by a series of in vitro and in vivo experiments. The miRNA profiles, RNA pull-down, RNA immunoprecipitation, serial deletion analysis, and luciferase analyses were used to investigate the potential mechanisms of MPRL. Results: We found that MPRL expression was significantly upregulated in TSCC cell lines treated with cisplatin and transactivated by E2F1. MPRL controlled mitochondrial fission and cisplatin sensitivity through miR–483-5p. In exploring the underlying interaction between MPRL and miR–483-5p, we identified that cytoplasmic MPRL directly binds to pre–miR–483 within the loop region and blocks pre–miR–483 recognition and cleavage by TRBP–DICER-complex, thereby inhibiting miR–483-5p generation and upregulating miR–483-5p downstream target-FIS1 expression. Furthermore, overexpression or knockdown MPRL altered tumor apoptosis and growth in mouse xenografts. Importantly, we found that high expression of MPRL and pre–miR–483, and low expression of miR–483-5p were significantly associated with neoadjuvant chemosensitivity and better TSCC patients’ prognosis. Conclusions: We propose a model in which lncRNAs impair microprocessor recognition and are efficient of pre-miRNA cropping. In addition, our study reveals a novel regulatory network for mitochondrial fission and chemosensitivity and new biomarkers for prediction of neoadjuvant chemosensitivity in TSCC. These findings uncover a novel mechanism by which lncRNA determines mitochondrial fission and cisplatin chemosensitivity by inhibition of pre-miRNA processing and provide for the first time the rationale for lncRNA and miRNA biogenesis for predicting chemosensitivity and patient clinical prognosis.

Artesunate (ART) is a sesquiterpene lactone isolated from the leafy portions of the Chinese herb Artemisia annua. Here, we evaluated the effect of ART on the prostate cancer (PCa) cell lines DU145 and LNCaP and explored its potential mechanisms. ART inhibited the viability and mobility of DU145 and LNCaP cells. Mechanistically, we found that UCA1, one of the most important lncRNAs in malignancies of the urinary system, may be a potential mediator contributing to the tumor suppressor function of ART. First, the UCA1 level was reduced significantly after being exposed to ART. In addition, UCA1 was up-regulated in prostate cancer tissues compared to hyperplastic prostatic tissues, and a higher UCA1 level predicted poor prognosis in PCa patients. Furthermore, reintroduction of UCA1 into PCa cells reversed the effect of ART on apoptosis and metastatic ability. Then we determined that the miR-184/Bcl-2 axis might be the downstream signaling pathway of UCA1 upon ART treatment. UCA1 binds to miR-184 through its seed sequences and may function as a sponge for miR-184.

Aberrant expression of the miR-129 family has been found in several types of cancer, yet its expression and potential biologic role in breast cancer remain largely unknown. In the present study, we found that miR-129-2 was consistently downregulated in the breast cancer specimens and cell lines. Overexpression of miR-129-2-3p markedly suppressed breast cancer cell proliferation and induced its apoptosis. In addition, a luciferase reporter assay revealed that miR-129-2-3p suppressed BCL2L2 expression. Furthermore, BCL2L2 was able to reverse miR-129-2-3p-mediated cell apoptosis, indicating that BCL2L2 plays a crucial role in mediating the tumor-suppressive role of miR-129-2-3p. Moreover, bisulfite DNA sequencing PCR (BSP) analysis identified that promoter hypermethylation was responsible for the downregulation of miR-129-2 in breast cancer. Collectively, our findings indicate that miR-129-2 is downregulated in breast cancer cells by promoter hypermethylation. Moreover, downregulation of miR-129-2 results in BCL2L2 overexpression and disease progression in breast cancer patients.

Mesenchymal stem cells (MSCs) have the ability to differentiate into multiple cell types, including osteogenic, chondrogenic and adipogenic lineages. Osteogenic differentiation of MSCs plays a critical role in bone tissue engineering. Inducing MSC osteogenesis represents a potential treatment that promotes bone formation and bone regeneration. Recently, long non-coding RNA (lncRNA) was shown to participate in the occurrence and development of various diseases. Different lncRNA expression patterns can regulate the cell cycle, proliferation, metastasis, immunobiology and differentiation. With the recent extensive study of lncRNAs, an increasing number of lncRNAs are being studied in the MSC field. Furthermore, some lncRNAs have been confirmed to regulate MSC osteogenesis. Therefore, here, we review research concerning lncRNA in osteogenic differentiation of MSCs and highlight the importance of lncRNA in bone formation and bone regeneration.

miRNAs that translocate from the nucleus to mitochondria are referred to as mitochondrial microRNAs (mitomiR). mitomiRs have been shown to modulate the translational activity of the mitochondrial genome, yet their role in mitochondrial DNA (mtDNA) transcription remains to be determined. Here we report that the mitomiR-2392 regulates chemoresistance in tongue squamous cell carcinoma (TSCC) cells by reprogramming metabolism via downregulation of oxidative phosphorylation and upregulation of glycolysis. These effects were mediated through partial inhibition of mtDNA transcription by mitomiR-2392 rather than through translational regulation. This repression required specific miRNA–mtDNA base pairing and Argonaute 2. mitomiR-2392 recognized target sequences in the H-strand and partially inhibited polycistronic mtDNA transcription in a cell-specific manner. A retrospective analysis of TSCC patient tumors revealed a significant association of miR-2392 and regulated mitochondrial gene expression with chemosensitivity and overall survival. The clinical relevance of targeted mitochondrial genes was consistently validated by The Cancer Genome Atlas RNA sequencing in multiple types of cancer. Our study revealed for the first time the role of mitomiR in mtDNA transcription and its contribution to the molecular basis of tumor cell metabolism and chemoresistance. Significance: These findings uncover a novel mechanism by which mitomiRNA regulates mitochondrial transcription and provide rationale for use of mitomiRNA and mtDNA-encoded genes to predict chemosensitivity and patient clinical prognosis.

AR-42 is a member of a novelly discovered class of phenylbutyrate-derived histone deacetylase inhibitors, and has a number of antitumor effects in a variety of tumor types; however, the role of AR-42 and its possible mechanisms have not been reported in the treatment of breast cancer. The aim of the present study was to investigate the antitumor effects of AR-42 and its associated mechanisms in breast cancer. MTT assays and colony formation assays were conducted to measure the proliferation of MCF-7 cells, and flow cytometry was used to analyze cell apoptosis. The results revealed that AR-42 induced cell apoptosis and suppressed cell growth in a dose- and time-dependent manner. Mechanistically, AR-42 treatment increased the acetylation of the p53 protein and prolonged the half-life of the p53 protein; furthermore, AR-42 treatment upregulated p21 and PUMA expression. Notably, AR-42 had a synergistic effect on MCF-7 cells in combination with fluorouracil, which is one of the most commonly used chemotherapeutic agents. In conclusion, the results indicated that AR-42 inhibits breast cancer cell proliferation and induces apoptosis, indicating that AR-42 is a potential therapeutic agent.

Purpose: Aspirin has recently been reported to reduce both the incidence and the risk of metastasis in colon cancer. However, there is no evidence at the cellular levels or in the animal models for such an effect of aspirin on cancer metastasis. Experimental Design: MTT assay, colony formation assay, and apoptosis assay were employed to analyze the effects of aspirin on the osteosarcoma cell viability in vitro. The NF-κB activity was measured by the NF-κB p65 luciferase reporter. Western blotting was used to analyze the proteins in cells. The migration and invasion abilities of osteosarcoma cells in vitro were measured by the Transwell assay. Xenograft-bearing mice were used to assess the roles of aspirin in both tumor growth and metastasis of osteosarcoma in vivo (n = 5–8 mice/group). An unpaired Student t test or ANOVA with the Bonferroni post hoc test were used for the statistical comparisons. Results: Aspirin reduced cell viability in a dose- and time-dependent manner in osteosarcoma cell lines, and aspirin synergistically sensitized osteosarcoma cells to cisplatin (DDP) in vitro and in vivo (P < 0.001). Moreover, aspirin markedly repressed the migration and invasion of osteosarcoma cells in vitro (P < 0.001), and dramatically diminished the occurrence of osteosarcoma xenograft metastases to the lungs in vivo (P < 0.001). Mechanistically, aspirin diminishes osteosarcoma migration, invasion, and metastasis through the NF-κB pathway. Conclusions: Aspirin suppresses both the growth and metastasis of osteosarcoma through the NF-κB pathway at the cellular level and in the animal models. Clin Cancer Res; 21(23); 5349–59. ©2015 AACR.

Dysregulation of SOX10 was reported to be correlated with the progression of multiple cancer types, including melanocytic tumors and tumors of the nervous system. However, the mechanisms by which SOX10 is dysregulated in these tumors are poorly understood. In this study, we report that SOX10 is a direct substrate of Fbxw7α E3 ubiquitin ligase, a tumor suppressor in multiple cancers. Fbxw7α promotes SOX10 ubiquitination-mediated turnover through CPD domain of SOX10. Besides, GSK3β phosphorylates SOX10 at CPD domain and facilitates Fbxw7α-mediated SOX10 degradation. Moreover, SOX10 protein levels were inversely correlated with Fbxw7α in melanoma cells, and modulation of Fbxw7α levels regulated the expression of SOX10 and its downstream gene MIA. More importantly, SOX10 reversed Fbxw7α-mediated suppression of melanoma cell migration. This study provides evidence that the tumor suppressor Fbxw7α is the E3 ubiquitin ligase responsible for the degradation of SOX10, and suggests that reduced Fbxw7α might contribute to the upregulation of SOX10 in melanoma cells.

About 50-70% of breast cancers are estrogen receptor α (ERα) positive and most of them are sensitive to endocrine therapy including tamoxifen. However, one third of these patients will eventually develop resistance and relapse. We found that the expression of miR-15a and miR-16 were significantly decreased in tamoxifen resistant ER positive breast cancer cell lines. Exogenous expression of miR-15a/16 mimics re-sensitized resistant cells to tamoxifen by inhibiting Cyclin E1 and B cell lymphoma-2 (Bcl-2) to induce cell growth arrest and apoptosis respectively. Further, we identified that a repressive member of E2F family, E2F7, was responsible for the suppression of miR-15a/16 cluster by competing with E2F1 for E2F binding site at the promoter of their host gene DLEU2. Moreover, high expression of E2F7 is correlated with high risk of relapse and poor prognosis in breast cancer patients receiving tamoxifen treatment. Together, our results suggest that overexpression of E2F7 represses miR-15a/16 and then increases Cyclin E1 and Bcl-2 that result in tamoxifen resistance. E2F7 may be a valuable prognostic marker and a therapeutic target of tamoxifen resistance in breast cancer.

Osteosarcoma (OS), which is the most common primary malignant bone tumor, has a high incidence of pulmonary metastasis. CCL18 (C-C motif chemokine ligand 18), which is secreted by tumor-associated macrophages (TAMs), has been found to be increased in various tumors and is associated with tumor metastasis. However, the role of CCL18 in OS remains unclear. Here, we evaluated the effect of CCL18 on the OS cell lines MG63 and 143B and explored its potential mechanisms. We found that CCL18 enhanced the proliferation and migration of OS cells and upregulated UCA1 through transcription factor EP300. Subsequently, we further revealed that the downstream Wnt/β-catenin signaling pathway participated in this process. In addition, the high expression of CCL18 in both tissue and serum from patients was closely related to pulmonary metastasis and poor survival in OS patients. The tumor xenograft models also showed that CCL18 promoted the metastasis of OS cells. Collectively, our study indicated that macrophage-derived CCL18 promotes OS proliferation and metastasis via the EP300/UCA1/Wnt/β-catenin pathway and that CCL18 may be used as a prognostic marker and therapeutic target of OS. KEY MESSAGES: CCL18 promotes proliferation and migration of osteosarcoma cells by EP300/ UCA1/ Wnt/β-catenin pathway. CCL18+ TAMs are significantly correlated with pulmonary metastasis and poor survival in osteosarcoma patients. CCL18 may be used as a prognostic marker and therapeutic target for osteosarcoma.

Background: NKG2D recognises several ligands, including polymorphic major histocompatibility complex class I chain-related chain-related proteins A and B (MICA/B) and unique long 16-binding proteins (ULBPs). These ligands are present on cancer cells and are recognised by NKG2D in a cell-structure-sensing manner, triggering natural killer (NK) cell cytotoxicity. However, the mechanisms that control the expression of NKG2D ligands in malignant cells are poorly understood. 1-α,25-Dihydroxyvitamin D3 (1,25(OH)2D3) was recently shown to enhance the susceptibility of melanoma cells to the cytotoxicity of NK cells. However, the function of 1,25(OH)2D3 in other cancers and its potential mechanisms of action remain unknown. Methods: The expression levels of miR-302c and miR-520c in Kasumi-1, K562, MCF7 and MDA-MB-231 cells were evaluated using quantitative real-time PCR. The targets of miR-302c and miR-520c were confirmed by luciferase reporter assay. The killing effects of NK92 cells against Kasumi-1, K562, MCF7 and MDA-MB-231 cells were examined using the CytoTox 96 Non-Radioactive Cytotoxicity Assay. The levels of cytokines IFN-γ and granzyme B, which indicate the activation of NK cells, were also measured by enzyme-linked immunosorbent assay. Results: Treatment with 1,25(OH)2D3 enhanced the susceptibility of both the haematological tumour cell line Kasumi-1 and solid tumour cell line MDA-MB-231 to NK92 cells. miR-302c and miR-520c expression was induced, and their levels inversely correlated with the levels of NKG2D ligands MICA/B and ULBP2 upon 1,25(OH)2D3 treatment. A luciferase reporter assay revealed that miR-302c and miR-520c directly targeted the 3′-UTRs of MICA/B and ULBP2 and negatively regulated the expression of MIA/B and ULBP2. Moreover, upregulation of miR-302c or miR-520c by transfection of their mimics remarkably reduced the viability of Kasumi-1 cells upon NK cell co-incubation. By contrast, the suppression of the activity of miR-302c or miR-520c by their respective antisense oligonucleotides improved the resistance of Kasumi-1 cells to NK cells. Conclusion: 1,25(OH)2D3 facilitates the immuno-attack of NK cells against malignant cells partly through downregulation of miR-302c and miR-520c and hence upregulation of the NKG2D ligands MICA/B and ULBP2.

Tumor-initiating cells (T-ICs), a subpopulation of cancer cells with stem cell-like properties, are related to tumor relapse and metastasis. Our previous studies identified a distinct profile of microRNA (miRNA) expression in breast T-ICs (BT-ICs), and the dysregulated miRNAs contribute to the self-renewal and tumorigenesis of these cells. However, the underlying mechanisms for miRNA dysregulation in BT-ICs remain obscure. In the present study, we demonstrated that the expression and function of miR-34c were reduced in the BT-ICs of MCF-7 and SK-3rd cells, a breast cancer cell line enriched for BT-ICs. Ectopic expression of miR-34c reduced the self-renewal of BT-ICs, inhibited epithelial-mesenchymal transition, and suppressed migration of the tumor cells via silencing target gene Notch4. Furthermore, we identified a single hypermethylated CpG site in the promoter region of miR-34c gene that contributed to transcriptional repression of miR-34c in BT-ICs by reducing DNA binding activities of Sp1. Therefore, miR-34c reduction in BT-ICs induced by a single hypermethylated CpG site in the promoter region promotes self-renewal and epithelial-mesenchymal transition of BT-ICs.

Metastasis is a multistep process involving modification of morphology to suit migration, reduction of tumor cell adhesion to the extracellular matrix, increase of cell mobility, tumor cell resistance to anoikis, and other steps. MicroRNAs are well-suited to regulate tumor metastasis due to their capacity to repress numerous target genes in a coordinated manner, thereby enabling their intervention at multiple steps of the invasion-metastasis cascade. In this study, we identified a microRNA exemplifying these attributes, miR-124, whose expression was reduced in aggressive MDA-MB-231 and SK-3rd breast cancer cells. Down-regulation of miR-124 expression in highly aggressive breast cancer cells contributed in part to DNA hypermethylation around the promoters of the three genes encoding miR-124. Ectopic expression of miR-124 in MDA-MB-231 cells suppressed metastasis-related traits including formation of spindle-like morphology, migratory capacity, adhesion to fibronectin, and anoikis. These findings indicate that miR-124 suppresses multiple steps of metastasis by diverse mechanisms in breast cancer cells and suggest a potential application of miR-124 in breast cancer treatment.

APC/C(Cdh1) plays a key role in mitotic exit and has essential targets in the G(1) phase; however, these mechanisms are poorly understood. In this report, we provide evidence that damaged DNA-binding protein 1 (DDB1) is capable of binding the WD40 domains of Cdh1, but not of Cdc20, through its BPA and BPC domains. Moreover, cells lacking DDB1 exhibit markedly elevated levels of the protein substrates of APC/C(Cdh1). Depletion of DDB1 in mitotic cells significantly delays mitotic exit, which demonstrates that the interaction between DDB1 and Cdh1 plays a critical role in regulating APC/C(Cdh1) activity. However, cells depleted of Cdh1 demonstrated no change in the UV-induced degradation of Cdt1, the main function of DDB1 as an E3 ligase. Strikingly, the APC/C(Cdh1) substrate levels are normal in cell knockdowns of Cul4A and Cul4B, which, along with DDB1, form an E3 ligase complex. This finding indicates that DDB1 modulates the function of APC/C(Cdh1) in a manner independent on the Cul4-DDB1 complex. Our results suggest that DDB1 may functionally regulate mitotic exit by modulating APC/C(Cdh1) activity. This study reveals that there may be cross-talk among DDB1, Cdh1, and Skp2 in the control of cell cycle division.

The Aurora B kinase plays a critical role in cell mitosis and spindle checkpoint. Here, we showed that the ubiquitin E3-ligase protein Skp2, also as a cell-cycle regulatory protein, was required for the activation of Aurora B and its downstream protein. When we restored Skp2 knockdown Hela cells with Skp2 and Skp2-LRR E3 ligase dead mutant we found that Skp2 could rescue the defect in the activation of Aurora B, but the mutant failed to do so. Furthermore, we discovered that Skp2 could interact with Aurora B and trigger Aurora B Lysine (K) 63-linked ubiquitination. Finally, we demonstrated the essential role of Skp2 in cell mitosis progression and spindle checkpoint, which was Aurora B dependent. Our results identified a novel ubiquitinated substrate of Skp2, and also indicated that Aurora B ubiquitination might serve as an important event for Aurora B activation in cell mitosis and spindle checkpoint.

It has been reported that lncRNA PANDAR (promoter of CDKN1A antisense DNA damage-activated RNA) is induced as a result of DNA damage, and it regulates the reparation of DNA damage. In this study, we investigated the role of lncRNA PANDAR in the progression of breast cancer and found that PANDAR was up-regulated in breast cancer tissues and cell lines. The knockdown of PANDAR suppresses G1/S transition of breast cancer cells. We demonstrated mechanistically that the regulation of G1/S transition by PANDAR was partly due to the transcriptional modulation of p16INK4A. Moreover, we showed that PANDAR impacted p16INK4A expression by regulating the recruitment Bmi1 to p16INK4A promoter. To our knowledge, this is the first study which showed the functional roles and mechanisms of PANDAR in regulating the progression of breast cancer. The PANDAR/Bmi1/p16INK4A axis could serve as novel targets for breast cancer therapy.

SUN2, a key component of LINC (linker of nucleoskeleton and cytoskeleton) complex located at the inner nuclear membrane, plays unknown role in lung cancer. We found that SUN2 expression was decreased in lung cancer tissue compared with paired normal tissues and that higher SUN2 levels predicted better overall survival and first progression survival. Overexpression of SUN2 inhibits cell proliferation, colony formation and migration in lung cancer, whereas knockdown of SUN2 promotes cell proliferation and migration. Additionally, SUN2 increases the sensitivity of lung cancer to cisplatin by inducing cell apoptosis. Mechanistically, we showed that SUN2 exerts its tumor suppressor functions by decreasing the expression of GLUT1 and LDHA to inhibit the Warburg effect. Finally, our results provided evidence that SIRT5 acts, at least partly, as a negative regulator of SUN2.Taken together, our findings indicate that SUN2 is a key component in lung cancer progression by inhibiting the Warburg effect and that the novel SIRT5/SUN2 axis may prove to be useful for the development of new strategies for treating the patients with lung cancer.

Terrein is a bioactive fungal metabolite isolated from Aspergillus terreus. Besides being a melanogenesis inhibitor, previous studies have revealed that terrein has antiproliferative effects on a number of types of cancer tumors. In the present study, the inhibitory effect of terrein on esophageal cancer was evaluated and the possible underlying mechanisms were investigated. The results revealed that terrein inhibited the proliferation of Eca109 esophageal cancer cells in a dose- and time-dependent manner. Mechanistically, terrein treatment led to the G2/M phase arrest of Eca109 cells by indirectly regulating cyclin B1 and phosphorylating the cell division cycle protein 2 genes. Notably, terrein exhibited a synergistic effect on Eca109 cells when combined with cisplatin, which is a commonly used chemotherapeutic drug. Taken together, these findings indicate that terrein suppresses the proliferation of esophageal cancer cells, and may prove to be a novel therapeutic approach for the treatment of esophageal cancer via inhibiting the proliferation of cancer cells.

// Pengnan Hu 1,2,3,* , Junjun Chu 1,3,* , Yanqing Wu 1,3 , Lijuan Sun 1,3 , Xiaobin Lv 1,3 , Yinghua Zhu 1,3 , Jingjing Li 1,3 , Qiannan Guo 1,3 , Chang Gong 1,3 , Bodu Liu 1,2,3 and Shicheng Su 1,3 1 Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China 2 Key Laboratory of Gene Engineering of Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, China 3 Breast Tumor Center, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China * These authors have contributed equally to this work Correspondence to: Shicheng Su, email: // Bodu Liu, email: // Keywords : LncRNA; NBAT1; breast cancer; metastasis Received : May 04, 2015 Accepted : August 26, 2015 Published : September 10, 2015 Abstract Long noncoding RNA NBAT1 (neuroblastoma associated transcript 1) regulates cell proliferation and invasion by interacting with PRC2 (polycomb repressive complex 2) member EZH2 (enhancer of zeste 2). Decreased expression of NBAT1 is associated with poor clinical outcome in neuroblastomas. However, the roles of NBAT1 in other cancers remain unknown. Here, we report that NBAT1 is down-regulated in various types of cancer. Particularly, reduced NBAT1 in breast cancer is associated with tumor metastasis and poor patient prognosis. In vitro, ectopic NBAT1 inhibits migration and invasion of breast cancer cells. Mechanistic study shows that NBAT1 is associated with PRC2 member EZH2 and regulates global gene expression profile. Among them, DKK1 (dickkopf WNT signaling pathway inhibitor 1) is found to be regulated by NBAT1 in a PRC2 dependent manner, and is responsible for NBAT1’s effects in inhibiting migration and invasion of breast cancer cells. Taken together, our study demonstrates that long noncoding RNA NBAT1 is a potential breast cancer prognostic marker, as well as a potential therapeutic target to inhibit breast cancer metastasis.

Breast cancer metastasis is a major cause of cancer-related death in women. However, markers for diagnosis of breast cancer metastasis are rare. Here, we reported that TET1, a tumor suppressor gene, was downregulated and hypermethylated in highly metastatic breast cancer cell lines. Moreover, silencing of TET1 in breast cancer cells increased the migration and spreading of breast cancer cells. In breast cancer clinical samples, TET1 expression was reduced in LN metastases compared with primary tissues. Besides, the methylation level of the TET1 promoter was increased significantly in LN metastases. Taken together, these findings indicate that promoter hypermethylation may contribute to the downregulation of TET1 and could be used as a promising marker for diagnosis in patients with breast cancer metastasis.